One objective of this invention is improved ease of hitching over ball hitches which must be lined up both horizontally and vertically to hitch the same with the old army type pendulum hitch.
The hitch hereof is very similar to a semi-trucktrailer fifth wheel which, when lined up vertically, needs only an approximate horizontal line-up. The "fifth wheel type" hitch hereof is unique in that it has a double pin which slides into the inverted "fifth wheel" which is located under the truck frame (instead of on top of the truck frame). Instead of the rear of the fifth wheel tipping down, the rear of the inverted fifth wheel tips up when unhitched. When the double pin of the trailer tongue is locked into the inverted fifth wheel, the hitching of the elliptical steering pulley system which steers the fron wheel assembly of the trailer is placed in operation.
Improved backability of the trailer is another advantage. The center of the rearwardmost wheel-assembly, or wheel-truck of the trailer is a pivot point during backing up.
The forward wheel assembly of the trailer is steered by the angle of the vehicle backing it. This lets the trailer back up as though it were a two-wheeled trailer.
Another objective is to provide a truck and trailer assembly which is more safe from jack-knifing and is more stable on all road conditions by having a large truck ahead of the loaded trailer, instead of a small tractor with a semi-trailer on it. There is then more control on the truck pulling the trailer which allows the handling of the trailer without as much of a problem of jack-knifing. The trailer also will steer the front wheels in small amounts, depending upon how much of jack-knife one is sliding into.
For example, when the rear end of the truck starts to slide to the left in the beginning of a jack-knifing, then the front wheels of the trailer will turn to the right at their forward ends as a result of the effect of the two elliptical pulleys of this invention, whereby the trailer wheels are then in a better angular position for resisting further jack-knifing. They are then in a position more transverse to the direction of a jack-knifing motion and less in alignment with such direction. By keeping the driver in control of the truck's steerability, the result is much lesser jack-knifing and safer public highway conditions.
The truck and trailer assembly hereof can be loaded by just dropping a ramp across between the trailer and truck. By just unhitching the trailer, one can back the truck up against the trailer while the trailer is backed up to a dock, allowing one to load the truck and trailer at one stop by having doors in both ends of the trailer and a door in the back of the truck, also the trailer can be left to be loaded in another location from the truck, and then the truck can be rehitched to the trailer.
An objective is to provide a hitch and steering system that could be used on many types of trailers, from camping trailers which are pulled either by some automobiles and pickups up to large stock trailers and horse trailers, and sizes all the way up to big commercial hauling trailers, such as grain trailers, livestock trailers, merchandise trailers and tank trailers.
An objective is to provide interchangeability of a trailer from one truck to another. This is possible, even through ellipses that are more circular will be used on trailers having front axles closer to their forward ends and is made possible because the entire elliptical pulley pulling assembly is mounted on trailer and tongue with nothing but uniform inverted "fifth wheels" mounted on the trucks.
An important feature is that the fifth wheel hereof is inverted as compared with prior art use in truck-to-trailer hitching.